Overview
Freshwater organisms are rapidly declining globally, and over 1/3 of all amphibian taxa are at risk of extinction. Rana boylii is a stream breeding frog native to CA and OR.

BACKGROUND
- Rana boylii provide a unique link with hydroclimatic change as their breeding phenology is tightly coupled with river hydrology. They have evolved strong breeding associations with changes in flow associated with rain or snowmelt cues in the spring.
- As one of the only obligate stream-breeding frogs in western North America, the foothill yellow-legged frog (Rana boylii Baird 1854) historically occurred in streams and rivers from Oregon to northern Baja California west of the Sierra-Cascade crest across a range of elevations from sea level to ~1400 m.
- Rana boylii have declined over 50% from the species former range (Davidson et al. 2005, Lind 2005). Many existing populations are small.
- Small populations with limited genetic diversity may have reduced adaptive potential and difficulty responding to future environmental change. Identifying these populations is crucial for effective conservation prioritization and management.
KEY QUESTIONS
- Can we better characterize range-wide genetic structure of R. boylii, and identify areas for prioritization?
- Has river (flow) regulation reduced connectivity and genetic health (diversity) of R. boylii?
- Can we quantify this genetic signature for specific hydrologic flow regimes?
Historical range for Rana boylii was broad, extending from Southern California all the way into Oregon, and from the coast to the Sierra Nevada.